/Engine/Source/Runtime/Engine/Classes/Components/HierarchicalInstancedStaticMeshComponent.h
Apply the results of the async build.
void ApplyBuildTreeAsync ( [ENamedThreads::Type](API\Runtime\Core\Async\ENamedThreads__Type) CurrentThread, const FGraphEventRef & MyCompletionGraphEvent, [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< FClusterBuilder, ESPMode::ThreadSafe > Builder, double StartTime )